Electrical measuring instrument.



' eilii thread or the like, or poinm' iii is oleo enrried by the bridge 23 n, esige? but the whole :ilmll he firmly lielil in posif iion wiul respect. to iie polo-nieces: and by e doublolieudeil boli ll in lille yoke. Euch-cling: the nrmnnri-a-core sind udnpled to swing' freeiy upon ein exis is the nvm-Lliure (foil '7. This i prefer to construe@ ot' come light metallic Homework, prei'ei'nbiyeinmini um, in the form of n hoop, upon which i 'ind im nanny turns of line instal-fired copper wire as is consu-aient. withy elio required onlibrniion of the inetrnmenh and the intei'isi-y oi" the magnetic elilol' force in order to 'produce ille desired reading, tilie biro ends o45/ille coil beingl liroughb out. to the two insulnntecl ixiiix-upriii;rs i2 anni 13, wound iu oppoeitedreunions about the nxle lli. The free ends of Lliese hair-springs nre connected to insulated wires ifrlie lAri-:ingement. being; such thm; when nn identi-irai circuitJ is closed, so ne to cause n momentary current to nnss :wound the two hninslirings, the mutuel attraction bevi/ een the successive coils of the huireprings in one will be neutralized ny tine current. pnsi-iing in the opposite direction in the ot hernan-swing., thereby eliminnliugreuyndditionnlstrnin or luck of :strain brought upon the spring. by its effortl Le return Lne armutnre-coil 7 imo its normal position'wheu ehe coil4 sli-ill have been deflected by u cul-rem traversing i'he neme. i'ie'two huir-springs 12 und 13, together with the nxle 14, ere carried by n 'lL-hb bridge 23, which is secured to the ermutnroccre hy binding,r it with a iight The aluminium rime und .nxle 11i and hun :i counterlmluncing- 'is-eight; 17 und segmental firm .18,hnvingperform ione for minute adjustment. The jewels 19 .receive flic hardened-steel pivote 20, upon which the entire movnble element ol1 bhe inv nlrmncni freely swings.

in order to incilimte the calibration of iny improved instrument, l employ alle standards 21, which I emisirncy by forming the yoke 3 ne io be raised :in these two points Lo uecure Lne griniueaerl .seele or dini 532 by ineens of two mijustingxnu'cws :imi nlm-5:, as shown in the drawings. lig; tilxie i'eiitiure of my in-` vcnion considera, le time and laboral-e saved in Lne calibration ot' the instrument, und grenier eccessi bility for repei rs ie thereby re|1- tiered.

I am invero ll'uiy nmny minor changes muy be mafie in lille construction of my improved electrical :mensili-ing,A instrument, and I lo not desire to limit, my invonpion in scope to the `exact domils of construction shown in the iereni; ligeros; but

Wlmi; I do cluim, und: desire to secure by Letters Potent of Lilo United Sintes, is-

1." ln un eleobricni measuring instrument, n, magneiic elci composed of'n. Vsectional permnnent magnet having a.' yoke' und 'permw .nent nmgnets secured to the yoke, poiepioees' for the permanent magnet; haring voppmiing conceive surfaces, and :i spherical armatureoore therefor, n circular arnmtnre adapted lo ronnie over the surface of mid core between eriidpole-pieces and sind nrnmturecore, Lerminut centimeters for Lne seid nrnmtinre4 beingiiifferc-ntinlly coiled about. the shaft of uniolnrnml nre so as to neutralize the effects of the mutual and self induction of the current-:4 cnrried by seid ileimi'mil oouiiuctorn;

substantially ns descr-ibdllq Y In un electrical measuring instrument,- n'nmunetic iclcl composed `ol' u sectional pen iii-nient magnet hzwiugn' yoke nini permunent. magnets secured lo the yokefnoeiieces for the permnneni ningnctlniving'- opponing concnve surf-(Lees, and el spherical zirnniiiure core thorefoign circulnrairnmmlre udiiptidlo rotaie euer the nui-fece of, eil-ifi core lm iweeu `said pnlefpiecen .und unid armuture-colfeerminail conductors for the Said iifinannre.liel in e diercnbinlly coiled about. the ehiift., of sind urinutureso ns'. to neutralize llie effects of che mutuel and self induutionlof the our renin corrieri by thesnid terminali conductors, l, anni nu adjustable dini for the suini instrni ment und arms depending from. the magnet, of the instrument. foi" securing ille dini; snif etfuntinlly is described.

In en electrical mensn'ring inn)rumeni,A

ulmugnetiic .eld composed of usecilionnl nel"a meinemJ magnet; having n yoke and permuneut. magnets secured to theyoke,`polepi,eceix for Elie permiinent magnet having oppoe'ing conceive surfaces, and u. spherical eriuznure-vy core therefor, .'L circuler urmniure aclupieil to rombo over the surface of finiti core ne* mrc-en seid pole-pieces und sniil urmnlsure` core, termino( conductors for lhe midnrmnture beingdillg'ereutinlly coiled uboot the slniftr of seid armature on ns to neutralize the effects of the mutuel und self induction of the currents carried by seidterminnl conductors., und en indicator forsaiifinstrument.carried by the armature, @nid erumtnre together with the said armature-core sind the enliq indicator being carried by sind pole-pieces emi removubly attached o o the uniti permanent, magnet; nbsmr tinlly as described.

Signed et, the city of New Yorin, `in l t-ne county -in? New York and State of New York, this 17th doy of August, A.. D. 1900.

FREDRYCK A. LA ROCHE. Witnesses:

LEWIS L. Pinnen, Jenn l. Roonnr. 

